iHeartRadio's number of registered users is up more than 50% from a year ago

With iHeartRadio, Clear Channel is looking to the Web to dial up growth.

On Tuesday the company said the online streaming service now has 50 million registered users, which is up more than 50% from the same time last year. The milestone comes as the traditional radio giant faces increasing competition in the online music space that includes Pandora Media Inc., Spotify and Beats Music.

The fast-growing service is still nowhere near Oakland-based Pandora's 77 million active users, and it's difficult to compare the two services because iHeartRadio has not disclosed how many people actively use the service each month.

Spotify, the Stockholm-based digital music company, recently said it has reached 10 million paying subscribers among its 40 million active users.

Established tech giants have been getting into the mix too.

In May, Apple Inc. confirmed plans to purchase Beats Electronics and streaming service Beats Music for $3 billion. At the time, Beats said it had brought in 250,000 subscribers since its January launch. Amazon.com Inc. has also launched a streaming music service.

But amid the milestones, growth figures and acquisitions, it remains to be seen how profitable the streaming music business can be.

Clear Channel, which has more than $20 billion in long-term debt, does not break out financial details for the service and Brian Lakamp, president of digital for Clear Channel, declined to reveal those figures.

Clear Channel has tried to make iHeartRadio its consumer-facing brand since it launched the service in 2011 to enable people to listen to its stations online from one place. It has added on-demand and discovery features to the service in the last year and even created a new music awards show that aired on NBC.

Clear Channel Media & Entertainment and Warner Music Group Corp., the world's third-largest record label, have entered a partnership that will let Warner promote music through the radio giant and take in revenue from terrestrial radio.

The companies said Thursday that Warner will share in revenue...

Clear Channel Media & Entertainment and Warner Music Group Corp., the world's third-largest record label, have entered a partnership that will let Warner promote music through the radio giant and take in revenue from terrestrial radio.